Staffing and equipment of the core The flow cytometry core was established in 2001 with two employees, one sorter, and one analyzer. This core has demonstrated exceptional growth since its inception through the methodical addition of new technologies, equipment, and staff, as well as fostering an ongoing expansion of the user base. As described in more detail in the staff curriculum vitae section of this report, the staff has now grown to 6 employees with over 90 years of combined flow cytometry experience, thus providing the DIR with an outstanding depth and breadth of cytometry experience. The number and type of instruments has also expanded greatly, as shown in Table 1 below. Table 1. Core Instrumentation Instrument Year Acquired Use and Description FACSAria 2 SORP 2010 Cell sorting, 5 lasers, 18 colors FACSAria 2/3 SORP 2012 Cell sorting, 5 lasers, 18 colors FACSAria Fusion 2015 (50% paid by NIDDK) Cell sorting with biohazard containment, 5 lasers, 18 colors FACSymphony 2018 Cell analysis, 6 lasers, 30 colors LSR Fortessa 2014 Cell analysis, 5 lasers, 18 colors Two Luminex 200 systems 2017 (acquired from surplus at no cost to NHLBI) Quantitative and multiplexed cytokine measurements Amnis Imagestream Mk II 2007 with upgrade in 2012 Imaging flow cytometry, 5 lasers, 10 colors Quanterix SIMOA 2015 (used model purchased) Ultrasensitive quantification of cytokines The NHLBI Flow Cytometry Core Facility provides investigators at the NHLBI access to state-of-the-art flow cytometry consultation to investigators who have cytometers available in their own laboratories or branches. The flow cytometry core provides cell sorting, immunophenotyping of up to 15 markers simultaneously, cell cycle analysis, apoptosis measurements, and a variety of other cytometric assays. The core also provides quantitation of soluble cytokines and chemokines by Luminex multiplex bead arrays and Quanterix Simoa, as well as imaging flow cytometry with the Amnis Imagestream cytometer. The flow cytometry core also performs developmental work on new flow cytometric assays, including high dimensional immunophenotyping,and rare event analysis of cells such as circulating endothelial cells using imaging flow cytometry. The core also is performing cutting edge immunology discovery work on novel lymphoyte subsets. The flow cytometry core provides full cytometry and immunoassay services 5 days per week from 8 am until 6:30 pm. Users wanting analytical cytometry services after these hours can access the laboratory using a card reader for ID badges once they have requested access and have been trained on the cytometers. Cell sorting is performed exclusively by the staff, and after hour sorting can be scheduled with advance notification (2 day). The core provides services to 55 NHLBI principal investigators from 9 branches and centers. The only center not using the core is the population studies center (Framingham study). NIDDK principal investigators currently number 31, and there are a total of 45 investigators from other institutes (Table 2). The 45 non-NHLBI, non-NIDDK PIs only use a combined 9% of the core billable hours. From 2014 to date the flow cytometry core has provided cytometry and immunoassay services to 135 principal investigators, trained 265 new users, contributed to 135 peer-reviewed publications and 4 book chapters, and has maintained state of the art services and implemented new technologies